Data-Informed Discovery of High-Performance Cu-Ligand Catalysts for Acetylene Hydrochlorination

Abstract

Understanding the relationship between catalyst structure and performance is essential for the rational design of active sites for high-performance Cu-ligand catalysts for acetylene hydrochlorination. Herein, two descriptors are informed by data to screen efficient ligands and predict high-performance Cu-ligand catalysts: (1) the reduction potential of Cu2+-Cu+ and catalytic performance were correlated in a volcano-like manner; (2) the C≡C bond length of C2H2 and catalytic performance were linearly related within the Cu2+-Cu+ reduction limit. By using the two descriptors, the MPPO (3-methyl-1-phenyl-2-phospholene 1-oxide) ligand was successfully identified and developed into an effective Cu-MPPO catalyst. The conversion of C2H2 of 96.11 % and the selectivity of VCM of 99 % were obtained under the conditions of 180 h−1, 180 °C, and VHCl: VC2H2 = 1.2. The C2H2 conversion was still above 90 % after running for more than 600 h at 50 h−1. The excellent activity and exceptional stability of the Cu-MPPO catalyst validate the developed model for optimal ligand selection. Detailed structural characterization and density function theory calculations of the designed catalysts were performed to reveal the relationship between catalyst structure and activity. The results indicated that the addition of MPPO altered the local microenvironment of Cu. The simultaneous increased electron density around Cu and Cl resulted in strengthened HCl adsorption and weakened acetylene adsorption, inhibiting the generation of carbon deposition. In addition, MPPO contributed to suppressing the reduction of Cu species, thus stabilizing the active species. This research provides valuable insights and reference strategies for screening efficient ligands in Cu-ligand catalysts.